The invention concerns an infusion bag, especially for tea, which has a top part with corners folded down and a middle part folded down over it, to which a string with two free ends is attached, which goes from one side of the top part, through a hole, forming a loop on the other side of the top part and back, whereby the two free ends are pulled through the loop placed over the top edge of the infusion bag and are pulled to form a knot. The invention also concerns a method of closing an infusion bag, especially for tea, closed on top by corners folded down and then a middle part folded down, with a string, preferably having a tag on the other end, by means of two needles.
It is known how to close infusion bags exclusively with a string. For this, the corners on top of the infusion bag are first folded down and then the middle part is folded over the folded down corners to make the closure of the infusion bag reliable. This closure is secured by a string that has several ways of being attached.
In one known embodiment in German Utility Model 296 13 448, the string on the top part of the infusion bag is attached there by means of a separate attachment string. This connection between the end of the string and the infusion bag cannot withstand high stresses and is technically expensive.
To create a simple way of attaching the string, it is known from EP 0 807 579 how to provide the folded top part with two recesses and place the infusion bag next to a tensed string in such a way that it runs at the height of the recesses and a tucking needle can be passed through each of the recesses, take the string and pull it through the recesses with both its ends. The free ends of the string pulled through the recesses in the infusion bag are attached to the tag, for example by welding or tacking. The disadvantage of this is that the attachment is loose and therefore not secure, and it is possible for the folded down areas on the top part to come unfolded, so the contents of the infusion bag can fall out or a loss of aroma and freshness can occur.
EP 0 691 268 discloses a string closure in which a needle goes through a single hole in the top part of the infusion bag, grasps the string behind and pulls it through the hole, forming a noose, which is then used to make a knot. The disadvantage of this is that it does not make sure that the folded down corners and the middle of the top part folded down over it are grasped together and with the bag by the string connection and are connected by the knot formed. The closure itself is not secure enough during folding, perforating and stringing with high manufacturing precision.
The problem of the invention is to provide a secure attachment between the folded down parts of an infusion bag and the bag itself with a string connection that can be made simply at a low technical cost and at high production speed.
The invention solves the problem with an infusion bag of the type mentioned at the beginning that has two holes made in the top part at a lateral distance next to one another to the left and right of the longitudinal axis of the bag that grasp one folded corner and the middle of the top part; that the string forms a loop with one end that goes through one hole and the other end through the second hole; that the loop is placed over the top edge of the infusion bag and both ends of the string are passed from below through the loop forming a double knot. The loop is preferably made of crossed string parts laid one over another, whereby one short end and one long end of the string can be provided, especially for attaching a tag to the long end of the string, and whereby to increase the safety of the knot, the short end of the string in the preferred embodiment is arranged in the string parts of the loop criss-crossed over one another under the long end of the string on the wall of the bag. With the invention, the attachment of the folded down corners and the folded down middle part to one another and to the bag is secure, and production is simplified because the comparatively thick, and hence difficult to tool, middle longitudinal seam of conventional bags need not be pierced or perforated. The knots keep the connection itself from loosening by two holes spaced apart and separate ends of the string ends that are doubled going through them, so that even if one end should come out of the loop, the knot through the second end of the string and the extra noose holds it secure.
Developing the known method described at the beginning, the method of solving the problem in the invention is characterized by the fact that: the end of the string is looped through a recess in a holder; by the fact that the top part of the infusion bag is inserted into the holder and the string is looped around the top edge of the infusion bag; by the fact that the string is then grasped on its free end and on its long continuous end by two holes in the top part that go through the folded down parts and the free end, as well as the continuous part that first goes into a loop and is then pulled all the way out of the infusion bag; and by the fact that the noose is finally tightened by pulling, especially on the continuous part. To grasp the string, two needles are preferably used that go through the infusion bag under the closed part of the loop, whereby the holder can have guide holes for the needles. To pull the string through, it must be cut on the continuous part, before the needles are pulled back at the latest. That way, the continuous part forms one long end of string, which can be used to attach a tag.
The method in the invention closes the folded down top part of the infusion bag exclusively using the string, and does not use extra string. The string is pulled through the top part of the infusion bag or pierces it with the needles, whereby the holder contains guide holes for the needles. The needles make only a simple motion to perforate the top part of the infusion bag, to allow a fast, simple sequence of movements. Previous perforation of the top part of the infusion bag is not essential. The top of the bag is securely closed by the two stitches to the right and left of the middle, whereby the folded down corners are also fixed. Attachment can be done in a continuous process at a calm machine pace and a high product count. The knot does not come loose due to the forces of friction even when slightly prestressed, i.e., when tightened loosely.